Abstract: A method of operating an electric power generation system (2). In one embodiment, a combustion chamber receives a combination of pressurized air (14) flow output from a compressor (12) and fuel (20) for combustion therein. The system (2) is operated at a relatively high steady state level of power output and then power is turned down by extracting a portion (34) of the pressurized air (14) flow before entry into the combustor (16). The method may further include throttling of air (14) flowing through the compressor (12) with inlet guide vanes (15). Features of the reduction in power include maintaining a characteristic combustor (16) minimum flame temperature with a volumetric percentage of NOx or CO emissions not exceeding those corresponding to the relatively high steady state operation.